Length requirements for tRNA-specific enzymes and cleavage specificity at the 3' end of turnip yellow mosaic virus RNA.

This paper describes the minimum length of the turnip yellow mosaic virus (TYMV) RNA necessary to fulfill the tRNA-like properties of the viral RNA: 50 to 75 nucleotides and 86 nucleotides from the 3' end of TYMV RNA are sufficient for adenylation and valylation respectively by the Escherichia coli system. The size of the tRNA-like fragments obtained in vitro in the presence of an E. coli, a reticulocyte or a chinese cabbage leaf extract has also been determined. Among the major fragments liberated from the 3' end of TYMV RNA by the three systems are fragments of 117 and 112 nucleotides. In addition, the E. coli extract liberates fragments of 139 and 61 nucleotides, and the reticulocyte lysate fragments of 109, 94, 84, 73 and 46 nucleotides. The cleavage of the viral RNA by several systems in vitro to yield RNA fragments encompassing the tRNA-like sequence suggests that such fragments might also be liberated in vivo.